Device for influencing the fuel delivery of an injection pump supplying the fuel for an internal combustion engine



. STAEGE ETAL 3,033,186

May 8, 1962 w DEVICE FOR INFLUENCING THE FUEL DELIVERY OF AN INJECTIQN PUMP SUPPLYING THE FUEL FOR AN INTERNAL COMBUSTION ENGINE 4 Sheets-Sheet 1 Filed June 5, 1958 1 06? fclnt May 8, 1962 w. STAEGE ETAL 3,033,186

DEVICE FOR INFLUENCING THE FUEL DELIVERY OF AN INJECTION PUMP SUPPLYING THE FUEL FOR AN INTERNAL COMBUSTION ENGINE Filed June 5, 1958 4 Sheets-Sheet 2 mam.-

y 1962 w. STAEGE ETAL 3,033,136

DEVICE FOR INFLUENCING THE FUEL DELIVERY OF AN INJECTION PUMP SUPPLYING THE FUEL FOR AN INTERNAL COMBUSTION ENGINE Filed June 5, 1958 4 Sheets-Sheet 3 Mi -t7 W. STAEGE DEVICE FOR INFLUENCING SUP ETAL 3,033,186 T E FUEL DELIVERY OF AN P NG THE FUEL FOR AN INTERNAL COMBUSTION ENGINE May 8, 1962 INJECTION PUMP 4 Sheets-Sheet 4 Filed June 5, 1958 DEVICE FOR INFLUENCKNG THE FUEL DELIV- ERY OF AN INJECTION PUMP SUPPLYING THE 2% FDR AN INTERNAL COMBUSTION EN- Werner fitaege, Freudenstadt, and Rudolf Schenk, Munich,

Germany, assignors to Kugelfischer Georg Schlifer dz Co., Schweinfurt, Germany Filed dune 5, 1958, Ser. No. 746,132 Claims priority, application Germany Feb. 7, 1958 17 Ciaims. (Cl. 123-140) With fuel injection pumps used in conjunction with internal combustion engines operating on gasoline as a fuel it is necessary, as has been known in the art, to adjust the rate at which fuel is delivered to the engine in accordance with the position of the throttle and the speed of the engine. To solve this problem it has already been proposed to use a control device comprising a three-dimensional cam or the like the shape of which is derived from an empirically determined relationship, the position of the said cam being adapted to be varied in relation to a follower pin or tracer member cooperating with the cam by cam adjusting forces derived from the two abovementioned controlling factors, namely the position of the throttle and the speed of the engine. Preferably the said three-dimensional cam surface is superimposed on a cylindrical surface, the relatively small control .pulses whose magnitude is determined by the changes in the speed of the engine being utilized to vary the angular position of the said cam. However, the said known devices of the type indicated do not take into account the necessity of effecting a compensation for the changes in the specific gravity of the combustion air which influence the composition of the fuel-air mixture under varying engine operating conditions. For example, if an internal combustion engine fitted with a fuel injection pump is operated at great altitudes, the reduction in the specific gravity of the air admitted into the engine requires a different relationship between the rate of fuel delivery and the volume of air drawn into the engine cylinders per unit time, if the correct mixture ratio is to be maintained. Furthermore, the known devices of the type mentioned do not comprise any means permitting the fuel-air ratio to be varied during the warming-up period of the engine, although it is known that the engine requires a richer mixture during warming up than after it has reached the proper operating temperature. Where attempts have been made in the past to have the controlling action of the follower member co-operating with the three-dimensional cam varied as a function of the specific gravity of the air drawn in by the engine, this factor has been utilized directly to vary the position of the adjusting member controlling the rate of delivery of the fuel injection pump, i.e. independently of the position of the said follower member. However, this method of influencing the rate of fuel delivery of the injection pump by an additional factor and independently of the movements of the follower member is not suitable for all possible operating conditions of the engine, since the controlling effect produced by the cam follower is changed by a constant quantity throughout the speed range of the engine, whilst actual operating conditions call for changes which are approximately proportional to the cam-induced movements of the cam follower. This proportionality must be variable depending on the varying conditions under which the engine is reice quired to operate. Prior art control devices have been incapable of meeting this requirement. It has, therefore, been necessary up to the present invention to design the said three-dimensional cam on the basis of a certain operating condition of the engine which was assumed to represent normal operating conditions.

It is one of the objects of the present invention to provide a control device which is adapted to take into account the aforementioned factors in the control of the rate of delivery of a fuel injection pump. According to the invention, in a device adapted to influence the rate at which fuel is delivered to an internal combustion engine by a fuel injection pump, in which device the position of a three-dimensional cam surface the shape of which is derived from an empiric relationship and which is preferably superimposed on a cylindrical surface, in relation to a cam follower member cooperating with the said cam surface is determined by the position of the engine throttle and the speed of the engine, the object of the invention is attained by providing for the controlling pulses to be transmitted from the said cam follower to the adjusting member of the fuel injection pump by way of control means including several measuring instrumentalities permitting the said controlling pulses to be varied as a function of the pressure and the temperature of the ambient air and as a function of the operating temperature of the engine.

In a specific embodiment of the invention, the said control device may comprise a set of barometric bellows which are exposed to atmospheric pressure and two sets of bimetallic capsules, one of said capsules being subject to the temperature of the induction air and the other capsule being subject to the operating temperature of the engine, the arrangement being such that the lengths of travel of all of these impulse-producing pick-ups are added to one another along a common operating axis. Also according to the invention, the controlling movements produced by the control device may be utilized, by changing the position of the pivotal axis of a lever member serving to transmit the said impulses from the said cam follower to the adjusting member of the fuel injection pump so as to vary the length of the lever arms which respectively co-operate with the cam follower on the one hand and the injection pump adjusting member on the other. Furthermore, it is advantageous according to the invention to have still another controlling influence to be exerted on the injection pump adjusting member during starting of the engine. According to the invention, this additional controlling action may be produced by a solenoid connected in circuit with the starter motor.

In another specific embodiment of the invention, the said cam follower member (which may take the form of a pin) may be adapted to be slidably movable parallel to the axis of the said cam surface which is rotatable in dependence on the engine speed and which is superim posed to a cylindrical surface, the said slidable movement of the cam follower being a function of the position of the engine throttle. In this embodiment, the pivotal axis of the said lever member may be either parallel or at right angles to the axis of the cam member.

According to the invention the said lever member may take the form of a single-arm lever. However, the said member may also be embodied in a two-armed lever, in which case one arm of the lever co-operates with the cam follower pin and the other arm co-operates with the controlled member. Where it is desired to have the rate of fuel injection varied by an additional agency during starting of the engine, the said lever member may be adapted, according to the invention, to be rocked about the point of contact between the lever member and the cam follower pin.

In the case of a multi-cylinder engine having a fuel injection pump the cylinders or pump elements of which are not arranged parallel to one another, but are arranged in a manner resembling the arrangement of the cylinders of an opposed piston engine or a l-type engine, there may be interposed between the lever member and the adjusting pins controlling the rate of fuel delivery of the pump elements, a regulating cone, this being also in accordance with the invention. With such an arrangement it is also possible to provide for a two-armed lever member to transmit the impulses derived from the cam follower pin to a regulating cone member co-operating with the said injection pump adjusting pins, there being superimposed on the periphery of the said regulating cone a three-dimensional cam surface which co-operates with the said adjusting pins, this cam surface being derived from an empiric relationship, and the angular position of the regulating cone being varied by the controlling movements produced by the control device. According to the invention, the said lever member may be supported by an eccentric pivot and may be adapted, during starting of the engine, to be rocked about the point of contact between the cam follower pin and the lever member by a rotary movement of the said eccentric.

The invention may be performed in various different ways but some particular embodiments will now be described by way of example with reference to the accompanying drawings.

In FIGS. 1 and 2 the reference character 1 denotes a substantially drum-shaped cam member in which a threedimensional cam surface the shape of which is derived from an empirically established relationship is superimposed on a cylindrical surface. The angular position of the said drum-shaped cam 1 at any given moment is a function of the speed of the engine; this efiect is achieved by means of a squirrel-cage rotor 2 which is driven by the engine and which applies a torque on a permanent magnet armature 3 corresponding to a tachometer drive, this torque being transmitted through a driving band 4 to a drum 5 in the interior of which is provided a spiral spring 6 which balances the said torque. Only if the speed of the engine varies will the equilibrium between the applied torque and the counter-action of the spring 6 be destroyed, with the result that any change in engine speed will produce a corresponding rotary motion of the shaft 7 carrying both the cam 1 and the drum 5. The cam 1 co-operates with a cam follower pin 8 which is arranged to be moved in a direction approximately parallel to the axis of the cam and throughout the length of the latter, this movement being effected by a lever arm 9 which supports the cam follower pin and which is rocked about its pivot in proportion to the changes in the position of the engine throttle corresponding to the position of a pedal 99. Members 2 to '7, and lever arm 9 constitute a device for varying the relative position of cam 1 and cam follower 8. The movements of the cam follower 8 which are produced in this manner and which are a function of the speed of the engine and the posi tion of the throttle, are not utilized directly to vary the delivery of the injection pump, but in the embodiment of FIGS. 1 and 2 these movements are transmitted to the injection pump adjusting or control pin 11 by the onearmed lever member It) in such a manner that every movement of the control pin 11 is proportional to a corresponding movement of the cam follower pin 8. This proportionality may be varied by moving the pivot 12 of the lever member in one direction or in the opposite direction as indicated by the double-headed arrow 13 in FIG. 1. For this purpose, the rod member of square cross-section which is guided in a suitable aperture provided in the wall 14 of a housing is shifted by a rod 26 of a control device including a plurality of elements (not shown in FIGS. 1 and 2) which are adapted to respond to the pressure and temperature of the ambient air and to the operating temperature of the engine, respectively, and to change the axial position of the member 15 accordingly. One embodiment of a control device of the type just described is illustrated in FIG. 4 to operate rod 26. If this arrangement causes the position of the pivot 12 of the lever member 10 to be changed, there will result a change in the ratio between the lengths of the lever arms respectively co-operating with the cam follower pin 8 and with the pump control pin 11; in other words, the proportionality with which the movements of the cam follower pin 3 are transmitted to the control pin 11 is changed.

The modified embodiment of the invention shown in FIG. 3, in which like reference numerals indicate parts that are identical with like parts in FIGS. 1 and 2, differs from the embodiment just described in that the pivot 12 of the one-armed lever member 10 does not extend parallel to but at right angles to the axis of the shaft 7 carrying the control cam 1. The cam follower pin 8 is not guided by a rockable lever as in FIG. 1 but by a rod member 16 of square cross-section the axial position of which is a function of the position of the engine throttle and of the angular position of the foot pedal 90. In this embodiment, the change in the ratio between the lengths of the erTective arms of the lever member 10 is not only brought about by displacing the pivot 12 under control of rod 26 of the control device but also by displacing the cam follower pin 8 from its original position to, say, the position indicated in chain lines at 8. With this arrangement the steepness of the contour of the threedimensional cam surface of the drum member 1 may be reduced in comparison to the embodiment of FIGS. 1 and 2.

FIG. 5 and MG. 4 show embodiments of the control system of the present invention which are preferably used in multi-cylinder fuel injection pumps. FIG. 4 also shows the arrangement and manner of operation of the various temperature and pressure responsive elements of the control device mentioned earlier. Disposed in a housing 17 of the control device is a set of barometric bellows 13 which is subjected to the pressure of the surrounding atmosphere through the hole 19; also disposed in the housing 17 are a set of bimetallic capsules 20 which are exposed to the air drawn in by the engine, and a set of bimetallic capsules 21 past which the engine coolant 21a fiows. The induction air is admitted to and exhausted from that chamber of the housing 17 containing the set of bimetallic capsules 20 through the connectors 22 and 23, respectively; the coolant 21a is admitted to and exhausted from the chamber containing the set of bimetallic capsules 21 through the connectors 24 and 25, respectively. The movements produced by the set of barometric bellows 18 and by the set of bi metallic capsules 20 surrounded by the induction air occur in the direction of the axis of the push rod member 26; a second push rod member 27 is provided which is associated with the set of bimetallic capsules 20 and which transmits its movements to a third push rod 31 through a transmitting member 31' which is slidably movable on a rockable lever 29 which is in turn pivotally mounted at 28. The push rod member 32 associated with the set of bimetallic capsules 21 is adapted to displace the transmitting cam member 30 along the rockable lever 29 against the action of a helical spring 33, any movement of the transmitting member 30 to the left in FlG. 4 causing the points of contact between the push rod members 27 and 31 on the one hand and the transmitting body on the other to be moved farther apart, because that portion of the transmitting cam member which is nearest to the pivot 23 of the rocking lever 29 is of conical configuration. This conical surface 34 merges towards the right into a cylindrical periphery 35. As soon as the engine has attained the required operating temperature, the push rod 32 of the set of bimetallic capsules 21 then having moved a predetermined distance, any further displacement of the transmitting cam member 3G against the action of spring 33 will then no longer produce any additional movement of the push rod 26. To permit free rocking movement of the lever 29 under the action of push rod 27, that end of the transmitting cam member 30 which faces and co-operates with push rod 32 has a part-spherical configuration.

The movements of the cam follower means 8 cooperating with the control cam 1 are transmitted to a twoarmed lever member 37 which is supported at 38 by the linkage lever 39 which latter is adapted to be rocked by the push rod 26 which acts against the push rod 41 which is in turn loaded by a helical spring 40. This arrange ment permits the pivot 33 of the lever member 37 to be moved in two opposite directions as indicated by the double-headed arrow 42. in FIG. 4, any such movement causing a change in the ratio between the lengths of the lever arms respectively co-operating with the cam follower pin 3 and the rod 43 carrying the regulating cone 44. The lever 39 is pivoted eccentrically at 45 to a rockable lever 46 one end of which is supported for rotation in a portion of the housing; the lever 46 is adapted to be moved by the plunger 47 of a solenoid 48 which is connected in circuit with the engine starter motor. Therefore, during starting of the engine, the lever 39 will be moved in the direction of arrow 49, this causing an additional rocking motion of the lever 37 about its point of contact with the cam follower means 8. The regulating cone 44 which is urged towards the lever 37 by a helical spring 50 may co-operate with any desired number of regulating control pins 11. Thus, the cone 44 serves only as a direction-changing cam member, the taper angle of the cone affording a predetermined transmission ratio in regard to the movements of the rod 43 carrying the cone. It will be understood that the regulating cone 44 has to be provided to permit the control device of the invention to be used to control an injection pump having a plurality of pump elements respectively controlled by the control pins 11.

In still another embodiment of the invention which is shown in FIG. 5, the lever member 51 is pivoted eccentrically at 52 to the rockable lever 46 which latter may be operated in the manner already described by the plunger 47 of a solenoid 48. Thus, during starting of the engine, the lever member 51 will again be rocked about its point of contact with the cam follower pin 8. However, except for the possible eccentric movement, the pivot of the lever member 51 is not displaceable. The movements transmitted from the control cam 1 through the cam follower pin 8 and the lever member 51 to the shaft 53 carrying the regulating cam means 54, which latter transmits such movements to the regulating pins 11, are in this embodiment influenced by means of a pinion 55 rigidly attached to shaft 53 and co-operating with a rack 56 which is in turn movable in the directions indicated by the double-headed arrow 57 against the action of the helical spring 58 by the control device as shown in the lower part of FIG. 4. The push rod 26 engages the lower end of rack bar 56 and influences the position of control cam 54 in accordance with the pressure acting on bellows 18, the temperature of the air acting on temperature-responsive element 2t), and the temperature of the coolant acting on temperature-responsive element 21. The helical spring 59 serves to maintain the shaft 53 in positive engagement with the lever member 51. As will be seen in FIG. 6, there are formed on the periphery of the regulating cam means 54 used in this embodiment as many empirically determined three-dimensional cam surfaces 60 (separated by inoperative surface portions) as there are regulating pins controlling the various injection pump elements, for example, two cam surfaces 60, each of which extends through about Depending on the angular position of the regulating cam means 54 established by rotation of the pinion 55, the cam means 54 will co-operate with the regulating follower pins 11 in accordance with a predetermined relationship. It will be appreciated that in this embodiment the movements produced by the temperature and pressure responsive control device, in contrast to the embodiments shown in FIGS. 1, 2 and 4 (where a proportional change is effected), may be utilized to effect changes in any desired manner in accordance with an empirically established relationship between the factors involved since the regulating cam means 54 has empirically determined cam surfaces 60. Cam means 54 is part of control means which further include members 55, 56, 58, lever means 51 and eccentric member 46, and the cam follower pin means 11 which control the fuel supply of the injection pumps. The control means is influenced by member 26 of the temperature and pressure responsive control device shown in detail in FIG. 4, and also by the cam follower means 8 whose position is determined by the rotary speed of the engine and by the throttle position. Consequently, the fuel supply is adjusted under consideration of all factors requiring a variation of the fuel supply.

It will be understood that modifications and variations may be effected without departing from the spirit and scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

We claim: v

1. Fuel supply control system for the fuel injection pump of a combustion engine having a throttle, the control system comprising, in combination, a cam means having a three-dimensional cam surface; cam follower means cooperating with said cam means; a device connected to said means for varying the position of said cam follower means relative to said cam surface, said device including a member controlled by the engine throttle, and a member controlled by the rotary speed of the engine so that the displacement of said cam follower means depends on the engine speed and on the position of the throttle; a control device including a barometric element responsive to atmospheric pressure, a first temperatureresponsive element adapted to be exposed to air, a second temperature-responsive element, and means for applying the engine coolant to said secondtemperature responsive element; and control means including another regulating cam means having a three-dimensional cam surface and being shifted and controlled by said elements and by said cam follower means, and other cam follower means engaging said cam surface of said other cam means and being displaced by the same dependent on the positions of said elements and of said first-mentioned cam follower means, said other cam follower means being adapted to be operatively connected to the fuel injection pump for controlling the fuel supply in accordance with the prevailing conditions.

2. Fuel supply control system for the fuel injection pump of a combustion engine having a throttle, the control system comprising, in combination, a cam means having a three-dimensional cam surface; cam follower means cooperating with said cam means; a device connected to said means for varying the position of said cam follower means relative to said cam surface, said device including a member controlled by the engine throttle, and a member controlled by the rotary speed of the engine so that the displacement of said cam follower means depends on the engine speed and on the position of the throttle; a control device including a barometric element responsive to atmospheric pressure, a first temperature-responsive element adapted to be exposed to air, a second temperature-responsive element, means for applying the engine coolant to said second temperatureresponsive element, first and second aligned members respectively controlled by said barometric element and by said first temperalure-responsive element and having spaced ends, and a cam member controlled and shifted by said second temperature-responsive element and located between said ends of said first and second aligned members so that at least one of said first and second members is displaced under control of said three elements; and control means including another turntable regulating cam means having another three-dimensional cam surface, other follower means engaging said other cam surface and being operatively connected to the fuel injection pump for controlling the fuel supply, and means for turning said other regulating cam means and for shifting said other cam means in axial direction, said last mentioned means being operatively connected to said one of said first and second members and to said firstrnentioned cam follower means and controlled by the same whereby the fuel supply is adjusted dependent on the position of said one member and of said first-mentioned cam follower means.

3. An apparatus as set forth in claim 2, said control means including a pinion means connected to said other regulating cam means for turning movement, a reel: bar meshing with said pinion means, and wherein said one member is operatively connected to said rack bar for moving the same.

4. An apparatus as set forth in claim 3, said control means including a lever means engaging said first-mentioned cam follower means and operatively connected to said other regulating cam means and said pinion means for shifting said other cam regulating means in axial direction while said pinion means remains in meshing engagement with said rack bar.

5. An apparatus as set forth in claim 4, said control means including an eccentric member supporting said lever means for turning movement, and a movable means connected to said eccentric member for turning the same, and adapted to be operatively connected to, and to be moved under control of means for starting the engine whereby the position of the fulcrum of said lever means and thereby the position of said other cam means and other cam follower means can be adjusted.

6. An apparatus as set forth in claim and including an electro-magnetic means operatively connected through said movable means to said eccentric member for turning the same, said electromagnetic member being adapted to be connected into the circuit of a starter motor for starting the engine.

7. An apparatus as set forth in claim 2 wherein said cam member has a conical portion and a cylindrical portion, and wherein said second temperature-responsive clement ifects shifting of said cam member to a position in which said ends of said connecting members abut on said cylindrical portion when a selected temperature of the coolant is reached so that said coolant has no influence on the fuel supply control when the selected temperature is reached.

8. An apparatus as set forth in claim 7 wherein said control means includes a third member controlled by said second temperature-responsive element and abutting said cam member for shifting the same, and wherein the face of said cam member on which said third member abuts is of part-spherical configuration, and including means supporting said cam member for angular movement about an axis located at the center of said part-spherical face.

9. Fuel supply control system for the fuel injection pump of a combustion engine having a throttle, the control system comprising, in combination, a cam means having a three-dimensional cam surface; cam follower means cooperating with said cam means; a device connected to said means for varying the position of said cam follower means relative to said cam surface in accordance with the position of the engine throttle and with the rotary speed of the engine; a control device including an element responsive to the temperature in the vicinity of the engine; and control means including another regulating cam means having a three-dimensional cam surface and shifted and controlled by said element and by said cam follower means and other follower means ongaging said cam surface of said other cam means and adapted to be operatively connected to the fuel injection pump for controlling the fuel supply in accordance with the prevailing conditions.

10. Fuel supply control system for the fuel injection pump of a combustion engine having a throttle, the control system comprising, in combination, a cam means having a three-dimensional cam surface; cam follower means cooperating with said cam means; a device connected to said means for varying the position of said cam follower means relative to said cam surface in accordance with the position of the engine throttle and with the rotary speed of the engine; a control device including an element responsive to the temperature in the vicinity of the engine; and control means including another regulating cam means having a three-dimensional cam surface and shifted and controlled by said element and by said cam follower means, and other follower means engaging said cam surface of said other can means and adapted to be operatively connected to the fuel injection pump for controlling the fuel supply in accordance with the prevailing conditions, said regulating cam means being turnable under control of said element, and axially shiftable under the control of said first-mentioned cam follower means.

ll. Fuel supply control system for the fuel injection pump of a combustion engine having a throttle, the control system comprising, in combination, a cam means having a three-dimensional cam surface; cam follower means cooperating with said cam means; a device connected to said means for varying the position of said cam follower means relative to said cam surface in accordance with the positon of the engine throttle and with the rotary speed of the engine; a control device for controlling the fuel supply and including elements responsive to temperature and barometric pressure in the vicinity of the engine; and control means including another regulating cam means having a three-dimensional cam surface and shifted and controlled by said elements and by said cam follower means and other follower means engaging said cam surface of said other regulating cam means and adapted to be operatively connected to the fuel injection pump for controlling the fuel supply in accordance with the prevailing conditions, said regulating cam means being turnable under control of said element, and axially shiftable under control of said first-mentioned cam follower means, said control means including adjustable means operatively connecting said first-mentioned cam follower means and said other regulating cam means, and electromagnetic means for adjusting said adjustable means and adapted to be connected into the circuit of the starter motor of the engine.

12. A fuel supply control system as set forth in claim 9 wherein said first-mentioned cam means is turnable; and including engine-driven means operatively connected to said first-mentioned cam means for turning the same between positions representing different engine speeds.

13. A fuel supply control system as set forth in claim 9 wherein said other regulating cam means have at least two three-dimensional cam surfaces; and wherein said other follower means include two follower pins respectively cooperating with said two three-dimensional cam. surfaces of said other regulating cam means, said follower pins being adapted to be respectively connected to different fuel injection pumps of the engine.

14. A fuel supply control system as set forth in claim 9 wherein said control means include a lever means for operatively connecting said first-mentioned cam follower means and said other regulating cam means for shifting said other regulating cam means in accordance with the positons of said firstunentioncd cam follower means.

15. A fuel supply control system as set forth in claim 10 and including a pinion fixedly connected to said other regulating cam means for turning movement, and a rack bar meshing with said pinion and operatively connected to said element to be shifted by the same whereby the angular position of said other regulating cam means is adjusted.

16. A fuel supply control system as set forth in claim 15 and including a lever means operatively connecting said first-mentioned cam follower means and said other regulating cam means for shifting said other regulating cam means in axial direction in accordance with the position of said first-mentioned cam follower means.

17. A fuel supply control system as set forth in claim 16 and including an eccentric member turnably support- References Cited in the file of this patent UNITED STATES PATENTS 2,245,562 Becker June 17, 1941 2,378,036 Reggio June 12, 1945 2,378,037 Reggio June 12, 1945 2,435,902 Reggio Feb. 10, 1948 2,670,724 Reggio Mar. 2, 1954 

